A Millard County sheriff's deputy has been killed in an ATV crash at the Little Sahara Sand Dunes, authorities said.

Paul Robison, 57, was riding with his wife on Saturday in the Sand Mountain area when the ATV overturned and landed on top of them, pinning him between a tree and the ATV, the Juab County Sheriff's Office said in a statement Monday.

Paramedics responded to the remote site but were unable to revive him.

"According to witnesses, Mr. Robison was unresponsive," Juab County Sheriff Alden Orme wrote.

Robison's body has been taken to the state medical examiner for an autopsy.

"A preliminary report from the Medical Examiner's Office indicated a medical condition might have contributed to his death," Orme said.

"It's a loss to us," said Millard County Sheriff Robert Dekker. "He's a good friend and a good brother in law enforcement."

Robison was at one time an FBI fingerprint technician and worked in the Alaska state crime lab but moved to Kanosh in 1991 to raise his family, Dekker said. He was a sergeant in the corrections division, working at the Millard County Jail. He had announced his retirement effective in August, the sheriff said.

"He and his wife were going to be doing a little bit of traveling," Dekker said, adding that Robison leaves behind a wife and two children.

Robison's death was one in a series of ATV-related accidents across the state over the weekend. In Garfield County, a woman was killed in a crash.

Deputies said Juliejo Ann Jackson, 32, of Cedar City, was killed while riding an ATV on Sunday on the Cooper Peak trail near Panguitch Lake. Deputies said she was turkey hunting with her husband on a rough, rocky part of the trail when her husband lost control and the ATV overturned on them. She was not wearing a helmet, and emergency crews were unable to revive her, the Garfield County Sheriff's Office said.

"With the ATV season upon us, it is crucial that those who are riding ATVs wear a helmet at all times. The tragedy (Sunday) at Cooper Peak is a haunting reminder of what can happen when someone does not wear their helmet," Garfield County Sheriff Danny Perkins said. "We strongly encourage all who enjoy the out of doors in our county on their ATVs to please wear your safety helmet and also obey all traffic rules."

Juab County sheriff's deputies responded Sunday to a crash at the sand dunes where a 30-year-old Spanish Fork woman broke both of her legs. She was flown by medical helicopter to Utah Valley Regional Medical Center, where she was last reported to be in stable condition.

E-MAIL: bwinslow@desnews.com